A modified chain aliphatic polyamine obtained by addition reaction of a
chain aliphatic polyamine having a specific structure and an unsaturated
hydrocarbon compound has a low viscosity and it provides, when used as a
curing agent for epoxy resin, an epoxy resin composition which can
provide an epoxy resin cured product having an excellent property.
Further, a modified chain aliphatic polyamine composition obtained by
addition reaction of a chain aliphatic polyamine having a specific
structure and an unsaturated hydrocarbon compound followed by the
removing step of unreacted chain aliphatic polyamine to reduce its amount
less than 2% by weight provides, when used as a curing agent for epoxy
resin, an epoxy resin composition which can provide an epoxy resin cured
product having an excellent property.